That would be the adapter plate....lol...foot...lol. I've got 2 of them right now but one is for the Chalet and will be used really soon and the other is for the non-running suburban...dealer price is around 3 bills....try the boneyards first or call my buddy dave at Jurassic truck parts...602-305-7210....tell him i sent ya..later.
AZBLAZER
1979 K5
1976 K5 Chalet
1972 K10 Suburban